p-Toluenesulfonic acid monohydrate

ReagentPlus®, ≥98%

Linear Formula:
CAS Number:
Molecular Weight:
Beilstein/REAXYS Number:
EC Number:
MDL number:
PubChem Substance ID:

Quality Level

vapor density

5.9 (vs air)

product line





103-106 °C (lit.)

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InChI key


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p-toluenesulfonic acid monohydrate may be used as a better alternative to Friedel-Crafts catalysts for the alkylation of the aromatic nucleus with activated alkyl halides, alkenes, or tosylates under mild conditions.


3, 15 kg in poly drum
5 g in glass bottle
100, 500 g in poly bottle

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ReagentPlus is a registered trademark of Sigma-Aldrich Co. LLC



Signal Word


Hazard Statements

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves


UN 2585PSN2 8 / PGIII

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis
Certificate of Origin
Detailed characterization of p-toluenesulfonic acid monohydrate as a convenient, recoverable, safe, and selective catalyst for alkylation of the aromatic nucleus.
Mahindaratne MPD and Wimalasena K.
The Journal of Organic Chemistry, 63(9), 2858-2866 (1998)
Hans H Adomat et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 902, 84-95 (2012-07-24)
Androgens are key mediators of prostate development and function, a role that extends to the development of prostate diseases such as benign prostatic hyperplasia (BPH) and prostate cancer. In prostate, DHT is the major androgen and reduction and glucuronidation are...
Mild C-H halogenation of anilides and the isolation of an unusual palladium(I)-palladium(II) species.
Robin B Bedford et al.
Angewandte Chemie (International ed. in English), 50(24), 5524-5527 (2011-05-14)
Pei Liu et al.
Organic & biomolecular chemistry, 10(24), 4696-4698 (2012-05-18)
A convenient one-pot Mannich-type-cyclization-oxidation tandem process has been developed for the synthesis of 1,3,5-trisubstituted pyrazoles derivatives from aldehydes, hydrazines and alkynes using p-toluenesulfonic acid monohydrate (PTSA) as a multifunctional catalyst. This method provides a flexible and rapid route to 1,3,5-trisubstituted...
Jhonny Azuaje et al.
ACS combinatorial science, 13(1), 89-95 (2011-01-21)
We document here the use of polymer-supported p-toluenesulfonic acid as a highly effective, robust, economical and eco-friendly isocyanide scavenger. The herein described strategy circumvent the intense and repulsive odor of volatile isocyanides, enabling simplified and odorless workup and purifications. The...

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